TED2018
Prosanta Chakrabarty: Four billion years of evolution in six minutes
Filmed:
Readability: 3.7
3,529,466 views
Did humans evolve from monkeys or from fish? In this enlightening talk, ichthyologist and TED Fellow Prosanta Chakrabarty dispels some hardwired myths about evolution, encouraging us to remember that we're a small part of a complex, four-billion-year process -- and not the end of the line. "We're not the goal of evolution," Chakrabarty says. "Think of us all as young leaves on this ancient and gigantic tree of life -- connected by invisible branches not just to each other, but to our extinct relatives and our evolutionary ancestors."
Prosanta Chakrabarty - Ichthyologist
Prosanta Chakrabarty studies fish to help explain the evolution of human beings and our planet. Full bio
Prosanta Chakrabarty studies fish to help explain the evolution of human beings and our planet. Full bio
Double-click the English transcript below to play the video.
00:13
If we evolved from monkeys,
why are there still monkeys?
why are there still monkeys?
0
1039
4286
00:17
(Laughter)
1
5349
1379
00:18
Well, because we're not monkeys,
2
6752
2088
00:20
we're fish.
3
8864
1150
00:22
(Laughter)
4
10038
1039
00:23
Now, knowing you're a fish
and not a monkey
and not a monkey
5
11101
2948
00:26
is actually really important
to understanding where we came from.
to understanding where we came from.
6
14073
4427
00:30
I teach one of the largest
evolutionary biology classes in the US,
evolutionary biology classes in the US,
7
18524
3737
00:34
and when my students finally understand
why I call them fish all the time,
why I call them fish all the time,
8
22285
4059
00:38
then I know I'm getting my job done.
9
26368
2177
00:40
But I always have to start my classes
by dispelling some hardwired myths,
by dispelling some hardwired myths,
10
28979
4634
00:45
because without really knowing it,
many of us were taught evolution wrong.
many of us were taught evolution wrong.
11
33637
4047
00:50
For instance, we're taught
to say "the theory of evolution."
to say "the theory of evolution."
12
38849
3428
00:54
There are actually many theories,
and just like the process itself,
and just like the process itself,
13
42944
3817
00:58
the ones that best fit the data
are the ones that survive to this day.
are the ones that survive to this day.
14
46785
3754
01:03
The one we know best
is Darwinian natural selection.
is Darwinian natural selection.
15
51241
3143
01:06
That's the process by which organisms
that best fit an environment
that best fit an environment
16
54963
3960
01:10
survive and get to reproduce,
17
58947
2220
01:13
while those that are less fit
slowly die off.
slowly die off.
18
61191
2666
01:16
And that's it.
19
64698
1176
01:17
Evolution is as simple as that,
and it's a fact.
and it's a fact.
20
65898
2944
01:21
Evolution is a fact
as much as the "theory of gravity."
as much as the "theory of gravity."
21
69785
4000
01:26
You can prove it just as easily.
22
74150
2031
01:28
You just need to look at your bellybutton
23
76205
2063
01:30
that you share
with other placental mammals,
with other placental mammals,
24
78292
2166
01:32
or your backbone that you share
with other vertebrates,
with other vertebrates,
25
80482
3020
01:35
or your DNA that you share
with all other life on earth.
with all other life on earth.
26
83526
3341
01:39
Those traits didn't pop up in humans.
27
87511
2213
01:41
They were passed down
from different ancestors
from different ancestors
28
89748
2756
01:44
to all their descendants, not just us.
29
92528
2149
01:47
But that's not really
how we learn biology early on, is it?
how we learn biology early on, is it?
30
95619
3374
01:51
We learn plants and bacteria
are primitive things,
are primitive things,
31
99017
3419
01:54
and fish give rise to amphibians
followed by reptiles and mammals,
followed by reptiles and mammals,
32
102460
3154
01:57
and then you get you,
33
105638
1783
01:59
this perfectly evolved creature
at the end of the line.
at the end of the line.
34
107445
2698
02:03
But life doesn't evolve in a line,
35
111032
2734
02:05
and it doesn't end with us.
36
113790
1636
02:08
But we're always shown evolution
portrayed something like this,
portrayed something like this,
37
116591
3460
02:12
a monkey and a chimpanzee,
38
120075
2388
02:14
some extinct humans,
39
122487
1236
02:15
all on a forward and steady march
to becoming us.
to becoming us.
40
123747
3252
02:19
But they don't become us
any more than we would become them.
any more than we would become them.
41
127621
3595
02:23
We're also not the goal of evolution.
42
131240
2401
02:27
But why does it matter?
43
135298
1501
02:28
Why do we need to understand
evolution the right way?
evolution the right way?
44
136823
2872
02:32
Well, misunderstanding evolution
has led to many problems,
has led to many problems,
45
140560
3548
02:36
but you can't ask that age-old question,
46
144132
4316
02:40
"Where are we from?"
47
148472
1707
02:42
without understanding
evolution the right way.
evolution the right way.
48
150203
2809
02:45
Misunderstanding it has led
to many convoluted and corrupted views
to many convoluted and corrupted views
49
153036
5856
02:50
of how we should treat
other life on earth,
other life on earth,
50
158916
3047
02:53
and how we should treat each other
51
161987
1865
02:55
in terms of race and gender.
52
163876
1666
02:59
So let's go back four billion years.
53
167253
3007
03:02
This is the single-celled organism
we all came from.
we all came from.
54
170927
3124
03:06
At first, it gave rise
to other single-celled life,
to other single-celled life,
55
174075
3325
03:09
but these are still evolving to this day,
56
177424
2492
03:11
and some would say
the Archaea and Bacteria
the Archaea and Bacteria
57
179940
2190
03:14
that make up most of this group
58
182154
1850
03:16
is the most successful on the planet.
59
184028
2123
03:18
They are certainly going
to be here well after us.
to be here well after us.
60
186175
2476
03:21
About three billion years ago,
multicellularity evolved.
multicellularity evolved.
61
189500
3680
03:25
This includes your fungi
and your plants and your animals.
and your plants and your animals.
62
193204
3111
03:29
The first animals to develop
a backbone were fishes.
a backbone were fishes.
63
197021
3769
03:33
So technically,
all vertebrates are fishes,
all vertebrates are fishes,
64
201385
3921
03:37
so technically, you and I are fish.
65
205330
3363
03:40
So don't say I didn't warn you.
66
208717
1698
03:43
One fish lineage came onto land
67
211526
2081
03:45
and gave rise to, among other things,
the mammals and reptiles.
the mammals and reptiles.
68
213631
3906
03:49
Some reptiles become birds,
some mammals become primates,
some mammals become primates,
69
217561
4324
03:53
some primates become monkeys with tails,
70
221909
2761
03:56
and others become the great apes,
including a variety of human species.
including a variety of human species.
71
224694
4793
04:01
So you see, we didn't evolve from monkeys,
72
229511
2376
04:03
but we do share
a common ancestor with them.
a common ancestor with them.
73
231911
2151
04:06
All the while, life
around us kept evolving:
around us kept evolving:
74
234824
2920
04:09
more bacteria, more fungi,
lots of fish, fish, fish.
lots of fish, fish, fish.
75
237768
3942
04:13
If you couldn't tell --
yes, they're my favorite group.
yes, they're my favorite group.
76
241734
2587
04:16
(Laughter)
77
244345
1001
04:17
As life evolves, it also goes extinct.
78
245370
2937
04:20
Most species just last
for a few million years.
for a few million years.
79
248331
3287
04:23
So you see, most life on earth
that we see around us today
that we see around us today
80
251642
2753
04:26
are about the same age as our species.
81
254419
2195
04:28
So it's hubris,
it's self-centered to think,
it's self-centered to think,
82
256958
3302
04:32
"Oh, plants and bacteria are primitive,
83
260284
2571
04:34
and we've been here
for an evolutionary minute,
for an evolutionary minute,
84
262879
2238
04:37
so we're somehow special."
85
265141
1443
04:39
Think of life as being this book,
an unfinished book for sure.
an unfinished book for sure.
86
267172
4317
04:44
We're just seeing the last
few pages of each chapter.
few pages of each chapter.
87
272085
3333
04:48
If you look out
on the eight million species
on the eight million species
88
276386
2262
04:50
that we share this planet with,
89
278672
1625
04:52
think of them all being
four billion years of evolution.
four billion years of evolution.
90
280321
4518
04:56
They're all the product of that.
91
284863
1719
04:59
Think of us all as young leaves
on this ancient and gigantic tree of life,
on this ancient and gigantic tree of life,
92
287386
4832
05:04
all of us connected by invisible branches
not just to each other,
not just to each other,
93
292242
4301
05:08
but to our extinct relatives
and our evolutionary ancestors.
and our evolutionary ancestors.
94
296567
3286
05:12
As a biologist, I'm still
trying to learn, with others,
trying to learn, with others,
95
300499
3357
05:15
how everyone's related to each other,
who is related to whom.
who is related to whom.
96
303880
3195
05:20
Perhaps it's better still
97
308831
2278
05:23
to think of us
as a little fish out of water.
as a little fish out of water.
98
311133
3696
05:26
Yes, one that learned to walk and talk,
99
314853
2920
05:29
but one that still has
a lot of learning to do
a lot of learning to do
100
317797
2349
05:32
about who we are and where we came from.
101
320170
2671
05:35
Thank you.
102
323348
1151
05:36
(Applause)
103
324523
3978
ABOUT THE SPEAKER
Prosanta Chakrabarty - IchthyologistProsanta Chakrabarty studies fish to help explain the evolution of human beings and our planet.
Why you should listen
Dr. Prosanta Chakrabarty is an Associate Professor and Curator of Fishes at the Museum of Natural Science and Department of Biological Science at Louisiana State University.
Chakrabarty is a systematist and an ichthyologist studying the evolution and biogeography of both freshwater and marine fishes. His work includes studies of Neotropical (Central and South America, Caribbean) and Indo-West Pacific (Indian and Western Pacific Ocean) fishes. His natural history collecting efforts include trips to Japan, Australia, Taiwan, Madagascar, Panama, Kuwait and many other countries. He has discovered over a dozen new species including new anglerfishes and cavefishes.
The LSU Museum of Natural Science fish collection that Chakrabarty oversees includes nearly half a million fish specimens and nearly 10,000 DNA samples covering most major groups of fishes. He earned his PhD at the University of Michigan and his undergraduate degree is from McGill University in Montreal. He has written two books including A Guide to Academia: Getting into and Surviving Grad School, Postdocs and a Research Job. He is also a former Program Director at the National Science Foundation. He was named a TED Fellow in 2016 and a TED Senior Fellow in 2018.
Prosanta Chakrabarty | Speaker | TED.com